Tailstock for lathes



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Dc; 18, 1945. w. F. GROENE TAILsTocK FOR LATHES Filed may 1o, 1945 5 sheets-sheet 2 IN VEN TOR. w MPM F. @Rome ATTORNEY w. F. GROENE TAILsToCK FOR LATHES Filed May`1o, 194; 5 sheets-sheet s INVEN TOR. WWU RM F.' G1R GENE.

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' I TAILsTQcK FoRLATEs Filed May 10, 1,943 5 Sheets-Sheet 4 IN VEN TOR.

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ATTORNEY l Dec. 18, 1945.l

w. F. GRoENE ,TAILSTOCK FOR LATHES 5 Sheets-Sheet 5 Filed May 10 1943 INVENTOR. I VUJRM F. GROENE. BY

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Patented Dec. l-8, 1945 f .UNITE-D# STATES Y PATENT f OFFICE TAILSTOCK FOR. LATHES AWilliam FQ Groene, Cincinnati, Ohio, assignorto The R. K. Le Blond Machine Tool Company, Cincinnati, Ohio, a corporation of Delaware Application May 10, 1943,- Serial No. 486,295-

6 claims. ('01, :i2-s1) Thlsiinvention pertains to tailstock for lathe andis particularly related to improvements in ,the mechanism for manipulating and operating the tailstock to carry out its various functions in alathe.

n rOnelof the chiefobjects of this invention is to providimproved clamping mechanism for locking the tailstock to the bed ways of the lathe in sucli'a wayas to require a minimum of effort and skillupon the part of the operator in eecting the :clamping operation of the tailstock onthe bed.- It is' an objecty in connection with this improvement to provide a gearing mechanism associated with the clamping of the tailstocks to the 4bed of the lathe which4 has a reduction factor to enhance the degree of clamping with a relatively minimum amount of effort on the part of the operator. It is also an object to arrange the `clamping mechanism so that the operating handles for locking the tailstock to the bed, may

be readilypositioned in a convenient location so asnot `to interfere with the proper operation and manipulation of the tailstock or with the Y work being done in the lathe.

' ing o f the tailstock barrel in the tailstock in no way a'iects the accurate positioning of the tailstock barrel on the proper axis of alignment of the lathe. Inthis connection it is an object to provide bearings for the tailstock barrel at eachend of the tailstock which may be readily adju'sted to zero clearance for accurate positive sliding of the tailstock spindle in the tailstock housing and to provide, intermediate said accurately fitting bearings, means for clamping the tailstock rbarrel against axial movement when it is properly seated in the center of the work piece to be turned in the lathe. Means are provided for accurately adjusting the'bearings carrying the tailstock spindle to take up any wear so as to maintain the continued accuracy of the tailstock and the location of its spindle at all times on the proper axis of rotationV of the lathe,

Further features and advantages of this inventionwill appear from a Vdetailed description of the` drawings in which:

Figure I is a front elevational view of the tailstock, particularly showing the clamping mechanism for locking the tailstock to the bed of the lathe and the clamping apparatus for locking the tailstock spindle against axial movementin -the tailstock body. l

Figure II is a plan Yview of the tailstock shown in Figure I, particularly illustrating the worm and angular rack mechanism and the f handwheel operating device for eiiectingeaxial adjustment of the tailstock spindle inthe tailstock housing for presenting its center to a work piece in the lathe.

Figure III is a left hand end view of the-tailstockv showinga portion of the clamping mechanism for locking the tailstock to the bed of the lathe as seen looking toward the center of the tailstock.

Figure IV is a fragmentary sectional view on the line IV-IV of AFigures I and II particularly showing the clamping and locking device for holding the tailstock spindle against axial movement n-the'tailstock body.

Figure V is a fragmentary sectional View on the line V-V of Figure II particularly showing the dial indicating means for accurate positioning of the tailstock spindle lengthwise in thetailstock housing.- i

Figure VI is an enlarged fragmentary sectional view on the line VI-VI of Figure II showing the detailed construction of the clamping mechanism for locking the tailstock body to the bed of the lathe. Y v

' The tailstock comprises a bottom I which appropriately rests on the ways 2 and 3 of the bed 4 of a lathe to slide there along while maintaining lthe center` 5 of the tailstock in accurate alignment with the work spindle axis 5a of Athe lathe. On the top surface 6 of the tailstock bottom is mounted the tailstock body 1 which may be moved crosswise of the lathe axis 5a on the tongue 8 of the bottom I which operates in the groove l.fl on the bottom of the tailstock body 'I by appropriate adjusting screws I0, as in a conventionalmanner forl tailstocks. This Aapparatus will not' be described'in further detail as it formsno specic part of the present invention. When in operation in the lathe the bottom I andV body portion 1 are rigidly held together so that in elect they Yfunction as one solid integral body and maybe considered as such for the purposes of this description. Y i

The 4tailstock I-'I may be rigidly clamped to the ways 2 and Ily of the bed 4 by means of a pair of identical clamps II, Figures I, III, and VI, which are each carried on a VT-slot bolt I2 and have bed engaging surfaces I3 engaging the bed underneath the ways 2 and 3 when the T T-slot bolt I2 is pulled upwardly. The T-slot bolt passes through a clearance hole I4 in the clamp so as to permit the sidewise adjustment of the tailstock body 1 on the bottom I as mentioned above.

Referring more specifically to Figure VI the T-slot bolt I2 engages the surface |5 of the clamp IIand has a threaded upper portion IB on which is threadedly mounted the tightening nut I1 having a gear Vportion ,I8 formed integral therewith on which are the gear teeth I9. The undersurface of the gear I8 bears against the thrust collar 2| carried on the surface 22 of the tailstock ybody 1 so as to take care of downward thrusts of the gear and nut I1 when the .gear I9 is driven to rotate it on the threaded portion I6 of the screw I2 to thus draw the clamp II upwardly rmly against the surfaces I3-1I3 against the bed 4 of the lathe. A suitable compression spring 23 is provided around the screw I2 and operates against Washers 24 and 25 to normally keep the bolt I2 and gear |8 in downward posi tion .so to permit the dropping ofthe clamp Il when loosened to permit the free slidingvof the tailstock along the bed of the lathe.

The gear I9 is actuated bya pinion 26 formed integral with the rock shaft 21 journaled in the l bearing portions 28 of the tailstock body 1 and journaled in a, pilot bearing 2-9 atits lower end also in this tailstock housing 1. On the upper end of the rock shaft 21 is nxed an operating handle 38 by which the shaft 21 may be rotated to Operate the gear |9 and thus tighten the bolt I2 to effect clamping of the tailstock on the bed of the lathe. It will be noted that the bearing 28 provided for the shaft 21 is relatively vlong and self supporting so that the shaft 21 may be raised to re-engage the gear 26 in a different relative position in the gear I9 so the control lever 30, may be kept in proper oriented position with respect to the tailstock body and other operating mechanisms thereof to place it in the most convenient andpower-applying position for the operator. Merely by lifting the handle and the shaft 21 the lever may be presented to any of the desired positions for tighteningor loosening the headstock clamp I I.

with this; construction there is a gear reduction between the gear 26 and I9 so that' high power may be applied to the gear I9 to tightsv en the bolt I2 by relatively light pressure on the operating handle 30. Furthermore, it is not necessary to remove a wrench each time and to aga-in place it upon a nut on top of the rock shaft 21 as the handle is nxed integrally with the rock shaft 21 Iand it is merely necessary for the operator to raise the shaft slightly in the bearing 28 to remove its gear 26 from engagement with the gear I9 and then to bring it back down again to re-engage it to a new position to eiect the continued tightening of the bolt I2 while still maintaining the operating lever 30 in the proper desired operating position on the tailstock.

Inthe upper portion of the tailstock body 1 is mounted the tailstock spindle or barrel 3| carrying the' usual lathe center 5. This tailstock spindle 3| is axially slidable in bearings 32 and 33 `as best shown in Figure I. The tailstock is provided with a saw slot 34 extending the full length of the rear portion of the tailstock behind the spindle 3| as best Seen in Figures II, III, and IV. Perpendicular to the slot 34 are adjusting screws 35 which may be tightened Aso as securely to hold the upper portion 1a to the tailstock body 1 and which when slightly loosenedffor-m a snug sliding bearing for the tailstock spindle 3| in the bearings 32 and 33. Once this adjustment has been accurately and carefully made the tailstock spindle will therefore .be accurately guided in sliding movement along the work spindle axis at all times. Any wear which may also occur in these bearings 32 and 33 may xbe readily taken up by appropriately adjusting the screws 35. Re-

ferring more specifically to Figure IV, there is shown the clamping mechanismv for locking the talstock spindle .3| against axial movement in the tailstock Tbody 1 when its center 5 is appropriately presented to a work piece in the lathe. A suitable key 36 is held in place by a clamping stud 31 lthreaded at 38 into the headstock body 1 and engages in a slot 39 formed longitudinally of the tailstock spindle 3| to prevent rotation of the spindle 3| in the tailstock duringr the operation'of the lathe. The upper portion of this stud 31 has a threaded portion 39a upon which operates the clamping handle 40 which thrusts downwardly against the thrust collar 4| carried a counter bore 42 formed inthe tailstock spindle 4clamp 43.` 'I his clamp is provided withan arcuate spindle engaging surface 44 which nicely slidingly fits against part Aof the periphery of the tailstock spindle 3| and has a foot 43a andanother foot 43bVwhich-engages asurface 45 Vformed by a slot 4.5, 45, and 41, Figure I, cut through the top of the tailstocktransverse to the bearing 32. This clampis normally pressed downwardin its middle portion by operating the clampingI handle 40 so as to bring the arcuate surface 44 tightly against the spindle 3| so as to lock it in any desired position whenA its center 5 vis set in the workpiece 'of the lathe.

By this arrangement it will be vnotedv that clamping force is provided directly overthe tail-I stock barrel and 'in a vertical direction so as not to interfere with the re1ativemovementofthe. work spindle in the bearings 32 'and 33 inthe event they would become slightly worn; It will be noted that with this design of clamp the 4clamping pressure may be applied substantially on top of the spindle '3| and very closelytheretq so as to provide a uniform down-clamping prese sure thereon rather than relying Yon vthe pinching together of the upper portion of the tailstock as in more conventional practice. v Also with this., general arrangement of the bearings 32 and 33; and the independent clamping mechanism as shown in Figure IV, when the tailstock spindle,- is loosened from theclamp 43 it will still be held. in accurate nicely sliding lposition in the bear@-i ings`32 and 33 for the initial .accurate settingv of the work prior to clamping. Thus the clamping action of the clamp 43 has no relative effect on changing the position of the` work spindle off the tailstock spindle 3| whether it isclamped orl not Y The tailstock spindle 3| lmay be actuated axially in the bearings 32 and r33 by a sui-table handwheel 46 which operates the wormshaft 41 carried-inA the sleeve 48 andl which has a `worm v49 which operates in the rack 5I)v cut on the bottom oflthe, Spindle'3l ina manner as fully set forth in Patent' 2,062`,' 790 dated December 1, 1936. Also, alopropriete dial indicating'mechanism as se'enfin. Figure `V 'is provided comprising anindicating dial 5| carried on a shaft 52l journaled inthe" bracket 53 mounted in the tailstock body 1 andV having a worm wheel 54 operating -ina worm 55' formed on the shaft 41 so that rotation of the handwheel 46 and the shaft 41 will indicate the relative travel of the tailstock spindle 3|'in thetaiistock body 1, as. fully shown in Patent'zedf 640 issuedJuly 29, 1941. i

I claim:

1. In a tailstock for a lathe, a tailstock body, means Vfor clamping said tailstock body to the bed of said lathe comprising, a clamp extending under the ways of said bed upon which said tailstock is mounted, a clamp bolt passing through said clamp and extending upwardly into a cavity in said tailstock body, means for drawing said bolt and clamp upwardly toward the underneath side of the ways of said bed comprising a gear journaled insaid tailstock body having a threaded bore operating around the threaded portion of said bolt, and means for rotating said gear manually by means of a rock shaft vertically reciprocatable in a journal bearing in said tailstock body, a pinion formed on said rock shaft, an operating shaft fixed on the upper end of said rock shaft, and means whereby said rock shaft may be raised or lowered in said journal bearings to engage its pinion in different relative positions of engagement with said gear so as to effect operation of said gear and clamping mechanism for any desired position of said operating handle with respect to said tailstock.

2. In a tailstock, a body, a pair of split bearings extending longitudinally of Said tailstock, a tailstock spindle axially reciprocable in said bearings, means for adjusting the split portion yof said bearings to eiect an accurate sliding engagement of said bearings with said spindle, and

means independent of said split bearing portions of said tailstock for clamping said spindle to said vtailstock body, said clamping mechanism comprising a clamp mounted on said tailstock body and having a surface engaging part of the periphery of said spindle for locking said spindle against axial movement when said clamp is operated and foot portions for spacing said clamp from said tailstock body.

3. In a tailstock, a body, a pair of split .bearings extending longitudinally of said tailstock, a

tailstock spindle axially reciprocable in said bearclamp comprising a springable clamp bar member having an arcuate surface engaging the periphery of said spindle and having abutment portions at each end thereof each side of said spindle engaging a surface on said tailstock body so that when unclamped said arcuate surface is normally disengaged from tight clamping engagement with said spindle, and clamping means comprising a manually operated nut and stud arrangement for drawing down the center portion of said clamp to engage its arcuate surface tightly on said spindle to lock it against axial movement in said tailstock body.

4. In a tailstock, a body, a spindle slidably fitting a bore of said body, said body being split axially of said spindle to form with said bore a pair of adjustable bearings for said spindle, means loperable to adjust said bearingsto effect an accurate sliding engagement between said bearings and spindle, and means independent of said split bearing portions of said tailstock forV clamping said spindle to said tailstock body, said clamping means having foot portions for` spacing said clamping means from said tailstock-body.

5. A tailstock for a lathe having spaced parallel ways, a tailstock body 'slidably guided by and along said ways, aclamp positionedbeneatli said ways, va threaded bolt passing through said clamp between said ways and into a chamber in said body, a gear in said chamber threadedly engaging said bolt, a rock shaft supported in said body for rotation and axial movement, said shaft having pinion means meshing with said gear means, said pinion means being withdrawable from mesh with said gear means on axial movement of said rock shaft.

6. A tailstock for lathes comprising, in cornbination, a tailstock body having a bore, said body being split to form with said bore a contractable bearing, a spindle slidably fitting said bore, means on said body operable to contract said bearing -to precisely mount said spindle for sliding adjustment, there being a kerf in said body transversely of and intersecting said bore, a spindle clamp fitting said kerf and partially surrounding said spindle, said clamp having spaced feet on opposite sides of said spindle and engaging the bottom of said kerf, and means operable to force said clamp into said kerf at al point between said feet, to

.thereby clamp said spindle in axially adjusted position.

WILLIAM F. GROENE. 

